[DiapDealer]

That seems to be the gist of the problem, actually. When trying to launch an epub externally, Mantano moves (or "downloads") the file to its own 'books' folder and imports it to its library from that location.

When importing an epub internally (using Mantano's normal import feature), it imports it into its library while leaving the physical file in whatever location it was found in.

I don't use Mantano/CC in that manner, so it isn't a deal-breaker of any kind for me, but I can certainly see how it might be a deal-breaker for others.

Still, I would recommend sticking with version 2.4.0 for while before deciding to abandon it completely. It may well be something that gets fixed in a future version. I understand you're already having other issues with Mantano, though, so you gotta do what you gotta do. But I can't help but think your other issues (forced closes, menus not appearing, and missing covers) would be resolved with a fresh, clean slate, "all residual Mantano files deleted" install, though. I've never had those kinds of issues with any version I've had. The only time I've ever had Mantano close on me was with a problem epub.